1. Field
Aspects of the present invention relate to a source gas supply unit, and a deposition apparatus and method using the same, and more particularly, to a source gas supply unit capable of supplying a constant amount of source gas, and a deposition apparatus and method capable of uniformly depositing a layer using the same.
2. Description of the Related Art
With the rapid development of electronic display industries, thin, light-weight flat panel displays (FPDs) have recently been used in place of a cathode ray tube (CRT). Examples of FPDs include a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode (OLED) display device. FPDs have mainly used as a display device for a television (TV), a computer monitor, or the like.
The OLED display device is a spontaneous light-emitting display device that electrically excites fluorescent organic compounds to emit light. The OLED display device displays an arbitrary image on a panel by forming an organic compound layer between a positive electrode (anode) and a negative electrode (cathode), injecting electrons and holes from the outside, and emitting light by the energy of electron-hole recombination.
The OLED display device includes an anode, an organic layer, and a cathode, which are stacked on a substrate, and may further include at least thin film transistor (TFT). The organic layer includes an organic emission layer. In this organic emission layer, the holes and the electrons are recombined to form excitons, and generate light. Here, to further increase luminous efficiency, the holes and electrons should be more smoothly transported to the organic emission layer.
To this end, an electron transport layer may be interposed between the cathode and the organic emission layer, and a hole transport layer may be interposed between the anode and the organic emission layer. Further, a hole injection layer may be interposed between the anode and the hole transport layer, and an electron injection layer may be interposed between the cathode and the electron transport layer.
As described above, the OLED display device is formed by stacking a plurality of layers, such as a conductive layer, an organic layer, and an insulating layer. As a typical method of forming a thin film on a substrate, physical vapor depositions (PVDs) are used. PVDs include methods such as evaporation, ion plating and sputtering, chemical vapor depositions (CVDs) based on gas reaction, etc.
The formation of the thin film using a conventional CVD is carried out by introducing a carrier gas into a canister in which a source for forming the thin film is stored, evaporating the source, supplying a mixed gas of the carrier gas and the evaporated source gas into a deposition chamber, and depositing the source on a substrate disposed in the deposition chamber. However, in the case of the CVD, the shape or capacity of the source is changed due to the introduction of the carrier gas. Thus, it is difficult to stably evaporate the source, and the source is therefore non-uniformly deposited on the substrate.